Negative concord and double clausal negation are separate phenomena, which show some striking similarities, the main similarity being the fact that negation is formally expressed more than once, but semantically only once. These similarities have led scholars to hypothesize on whether and how these two are related. In this chapter some issues in the diachrony of both processes are discussed. On the basis of a survey of 103 non-European languages it is concluded that NC cannot be considered to be a necessary condition for DN nor for preverbal negation, thus refuting claims that have been proposed in the literature. The peculiar constellation found in French, in which a new negator grew out of NC concord, was not found in any other language of the sample, not even Ewe and Karok, the two other languages that have both NC and DN. It is further suggested that DN may be more frequent than NC and it is argued, against other claims in the literature, that the strategy of expressing clausal negation with only negative pronouns or adverbs is not only typical for Europe but also for the Americas and that it is also found in verb-initial languages.